The reticular thalamic nucleus projects to the contralateral dorsal thalamus in macaque monkey.

This study demonstrates, using the retrograde transport of horseradish peroxidase conjugated to the lectin wheat germ-agglutinin (WGA-HRP), that the reticular thalamic nucleus (RE) projects to the contralateral dorsal thalamus in macaque monkeys. Retrogradely labeled neurons were found in the RE nucleus following WGA-HRP injections confined to the contralateral dorsal thalamus. In light of the currently hypothesized role of the RE nucleus in the genesis of spindling rhythmicity during EEG-synchronized sleep, this findings suggests that the RE nucleus contributes to the bilateral synchrony of spindle waves through its contralateral dorsal thalamic projection.